1. Field of the Invention
The present invention relates to a silicone resin composition, an encapsulating layer, a reflector, and an optical semiconductor device, to be specific, to a silicone resin composition, an encapsulating layer made from the silicone resin composition, a reflector containing the silicone resin composition, and an optical semiconductor device including the silicone resin composition, the encapsulating layer, and the reflector.
2. Description of Related Art
Conventionally, as an encapsulating material for encapsulating an optical semiconductor element such as a light emitting diode (LED), a silicone resin having an excellent transparency has been used. The silicone resin is in a liquid state at room temperature. The silicone resin is applied to the optical semiconductor element to be then cured by heating, so that the silicone resin encapsulates the optical semiconductor element.
In view of storage stability and handling ability, a silicone resin in a solid state at room temperature is also used. As the silicone resin in a solid state, for example, a silsesquioxane-containing polymer obtained by allowing a pentacyclo[9.5.1.13.9.15.15.17.13]octasiloxane to react with a 1,3-divinyltetramethyldisiloxane has been proposed (ref: for example, Japanese Unexamined Patent Publication No. 2000-154252).
Also, a polysiloxane obtained by allowing a hydrogenated octasilsesquioxane to react with a disilanol has been proposed (ref: for example, Japanese Unexamined Patent Publication No. 2002-69191).
The encapsulating materials proposed in Japanese Unexamined Patent Publications No. 2000-154252 and No. 2002-69191 are plasticized by heating to thus encapsulate the optical semiconductor element.